Automatic rolling fifth wheel hitch

ABSTRACT

A fifth wheel hitch is shown and described. The fifth wheel hitch may include a base frame configured to be secured to a load bed of a towing vehicle, a trolley operatively engaged with the base frame, the trolley adapted to move along the base frame between first and second positions, and a cam member attached with the base frame, the cam member having a cam path. The fifth wheel hitch may also include a cam follower coupled with the trolley, the cam follower operatively engaged with the cam path, and a fifth wheel head pivotally coupled with the trolley, where the trolley is moved between the first and second positions in response to pivoting of the fifth wheel head.

This application is a continuation of U.S. application Ser. No.13/834,407, titled “Automatic Rolling Fifth Wheel Hitch,” which wasfiled on Mar. 15, 2013, which is hereby incorporated by reference in itsentirety.

FIELD OF INVENTION

The present invention relates generally to a fifth wheel hitch and, moreparticularly, to an automatically rolling fifth hitch for moving fifthwheel trailer in a predetermined manner in response to predefinedmovements.

BACKGROUND

The towing industry has developed a number of methods and apparatusesfor securing a towed vehicle to a towing vehicle. One particularlyprevalent towing apparatus is a fifth wheel hitch. The fifth wheel hitchis normally positioned in a load bed of a towing vehicle and securedeither to the load bed or directly to the frame of the towing vehicle. Afifth wheel trailer typically includes a king pin that operativelycouples the towed vehicle to the towing vehicle.

Fifth wheel hitches may normally be arranged such that the king pin isaligned over or near the rear axle and approximately equidistant betweenthe rear wheels of the towing vehicle. Placing the king pin over therear axle may also provide for sufficient clearance between the frontedge of the trailer and the rear edge of the towing vehicle cabin whenstandard sized towing and towed vehicle are involved.

However, there are more towing vehicles on the market that includeextended cabs having an expanded interior cargo volume. These extendedcab towing vehicles, however, are typically built on a standardwheelbase chassis. This results in the load bed being shorter thanstandard towing vehicles. These shorter load beds result in the towingvehicles not having sufficient clearance between the axle and the rearof the cab to allow the towed vehicle to pivot appropriately.

Current prior art systems attempt to adapt fifth wheel trailers to shortbed pickup trucks, but have shortcomings. For example, some systems usea hydraulically operated sliding base to force the hitch assemblyrearward away from the towing vehicle cab. Such a system, however, isexpensive and difficult to maintain. Further these systems often requireoperator intervention, which could make it generally ineffective.

Another prior art system uses a sliding base that requires the operatorto exit the towing vehicle, unlock the base, lock the brakes on thetowed vehicle and pull the towing vehicle forward. This temporarilymoves the pivot point rearward so that the towed vehicle can pivotrelative to the towing vehicle. However, before resuming normaloperation, the operator must lock the towed vehicle brakes, back thetowing vehicle towards the towed vehicle, again exit the towing vehicleand lock the sliding hitch. This is extremely inconvenient.

Still further, other prior art systems require sliding mechanisms onwhich the fifth wheel hitch engages to move the fifth wheel hitchrearward during certain conditions. These systems, however, may besubject to premature wear and constant maintenance. The slidingarrangement is often subject to accumulation of debris, which maynegatively impact the overall function of the sliding arrangement. Thesesliding systems also utilize cam paths that are generally linear. Thesegenerally linear cam paths limit the distance the fifth wheel hitch maytravel rearward during operation. Further still, these prior art systemsmay be limited in their stability, especially, from an operator'sperspective.

Accordingly, there exists a need for an improved automatic fifth hitchassembly that allows towing vehicles with short load beds to effectivelytow towed vehicles. Specifically, there is a need for an automatic fifthwheel hitch that is positionable to maintain the appropriate operativeposition of the towed vehicle relative to the towing vehicle that isrobust, easy to maintain and does not require operator intervention.Further, there is a need for an automatic fifth wheel hitch assemblythat is able to move rearward a greater distance to allow sufficientclearance between the towing vehicle cab and towed vehicle.

SUMMARY

A fifth wheel hitch is shown and described. The fifth wheel hitch mayinclude a base frame configured to be secured to a load bed of a towingvehicle, a trolley operatively engaged with the base frame, the trolleyadapted to move along the base frame between first and second positions,and a cam member attached with the base frame, the cam member having acam path. The fifth wheel hitch may also include a cam follower coupledwith the trolley, the cam follower operatively engaged with the campath, and a fifth wheel head pivotally coupled with the trolley, wherethe trolley is moved between the first and second positions in responseto pivoting of the fifth wheel head.

A fifth wheel hitch may include a base frame securable to a load bed ofa towing vehicle, the base frame including a channel, a trolley having aplurality of rollers, the rollers operatively engaged with the channel,where the trolley is moveable between first and second positions withrespect to the base frame, and a cam path, the cam path having a firstportion. The fifth wheel hitch may also include a cam follower coupledwith the trolley, the cam follower operatively engaging the firstportion of the cam path, where pivoting of the cam follower releases thecam follower from the first portion permitting movement of the trolleyfore and aft between the first and second positions.

A fifth wheel hitch may include a base frame securable to a load bed ofa towing vehicle, the base frame including a channel, a trolleyoperatively engaged with the channel, where the trolley is positionablebetween first and second positions with respect to the base frame, and afifth wheel head pivotally coupled to the trolley. The fifth wheel hitchmay also include a cam path, the cam path having a first portion, and acam follower coupled with the trolley and engaged with the cam path,where pivoting of the fifth wheel head moves the cam follower from thefirst portion causing the trolley to move between the first and secondpositions.

A fifth wheel hitch may include a base frame securable to a load bed ofa towing vehicle, the base frame including a channel. The fifth wheelhitch may also include a fifth wheel head operatively coupled with thebased frame, where the fifth wheel head is positionable fore and aftbetween first and second positions along the channel.

DESCRIPTION OF THE DRAWINGS

Operation of the invention may be better understood by reference to thefollowing detailed description taken in connection with the followingillustrations, wherein:

FIG. 1 is a perspective view of an automatic rolling fifth wheel hitchselectively secured with a load bed of a towing vehicle.

FIG. 2 is a perspective view of the automatic rolling fifth wheel hitch.

FIG. 3 is a partially exploded perspective view of the automatic rollingfifth wheel hitch.

FIG. 4 is a partially exploded view of a base frame and trolley of theautomatic rolling fifth wheel hitch.

FIG. 5 is a perspective view of a trolley of the automatic rolling fifthwheel hitch.

FIG. 6 is a perspective view of the base frame of the automatic rollingfifth wheel hitch.

FIG. 7 is a partially exploded view of a portion of the automaticrolling fifth wheel hitch.

FIG. 8 is a top view of embodiments of a cam plate.

FIG. 9 is a top view of embodiments of a cam plate.

FIG. 10 is a top view of embodiments of a cam plate.

FIG. 11 is a graphical representation of change of angle versus traveldistance for a cam path of the cam plate of FIG. 8.

FIG. 12 is a graphical representation of change of angle versus traveldistance for a cam path of the cam plate of FIG. 9.

FIG. 13 is a graphical representation of change of angle versus traveldistance for a cam path of the cam plate of FIG. 10.

FIG. 14 is a perspective view of embodiments of an automatic rollingfifth wheel hitch.

FIG. 15 is a partially exploded view of a base frame and trolley of theautomatic rolling fifth wheel hitch.

FIG. 16 is a bottom view of the automatic rolling fifth wheel hitch ofFIG. 14.

DETAILED DESCRIPTION

Reference will now be made in detail to exemplary embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. It is to be understood that other embodiments may be utilizedand structural and functional changes may be made without departing fromthe respective scope of the invention. Moreover, features of the variousembodiments may be combined or altered without departing from the scopeof the invention. As such, the following description is presented by wayof illustration only and should not limit in any way the variousalternatives and modifications that may be made to the illustratedembodiments and still be within the spirit and scope of the invention.

An automatic rolling fifth wheel hitch 100 is shown in FIGS. 1-3. Theautomatic rolling fifth wheel hitch 100 may attach to a load bed 104 ofa towing vehicle 108 in any appropriate manner. By way of a non-limitingexample, a pair of rail members 112 may be selectively attached to theload bed 104 in any appropriate manner, including, without limitationutilizing fasteners, securement devices or the like. The rail members112 may extend transversely across the load bed 104 as shown in FIG. 1.The rail members 112 may be configured to attach a standard fifth wheelhitch as well as the automatic rolling fifth wheel hitch 100 or may bespecifically configured for the automatic rolling fifth wheel hitch 100.The automatic rolling fifth wheel hitch 100 may be selectively attachedto the rail members 112 in any appropriate manner; such as by way of anon-limiting example via fasteners (not shown). Any appropriateconfiguration of fasteners may be used—the present teachings are notlimited to a specific configuration of fasteners.

The automatic rolling fifth wheel hitch 100 may include a base frame 120selectively secured to the rail members 112. The base frame 120 mayinclude at least one bracket 124, including, without limitation twopairs of brackets 124 attached thereto. The brackets 124 may attach withthe rail members 112 through the use of fasteners (not shown).Specifically, each of the brackets 124 may include a leg 128 attachedthereto in any appropriate manner, including, without limitation beingintegrally formed therewith. The legs 128 may be insertable into therail members 112. Fasteners may then be inserted into and through thelegs 128 and rail members 112 selectively securing the automatic rollingfifth wheel hitch 100 with the rail members 112 and the load bed 104 ofthe towing vehicle 108. This arrangement may make it easy to remove theautomatic rolling fifth wheel hitch 100 when not needed.

The automatic rolling fifth wheel hitch 100 may include a trolley 132operatively engaged with the base frame 120 as described in more detailbelow. The automatic rolling fifth wheel hitch 100 may further include afifth wheel head 136 pivotally attached with the trolley 132. The fifthwheel head 136 may be of any appropriate configuration such that a kingpin of a towed vehicle may operatively engage with the fifth wheel head136 resulting in the towing vehicle 108 being capable of towing thetowed vehicle. By way of a non-limiting example, the fifth wheel head136 may be of a configuration as shown and described in any one of: U.S.patent application Ser. No. 13/190,878 (Publication No. 20120018979)entitled “Fifth Wheel Hitch Isolation System,” filed Jul. 26, 2011; U.S.patent application Ser. No. 13,190,919 (Publication No. 20120018978)entitled, “Fifth Wheel Hitch Retention System,” filed Jul. 26, 2011; andU.S. patent application Ser. No. 13/191,009 (Publication No.20120018977) entitled “Fifth Wheel Hitch Skid Plate Cover,” filed Jul.26, 2011, all of which are hereby incorporated by reference. Further,the fifth wheel head 136 may be of a configuration as shown anddescribed in all of the applications incorporated by referenceimmediately above. However, the present teachings are not limited tothese disclosed configurations of the fifth wheel head 136. Anyappropriate configuration may be used.

As shown in FIG. 3, the fifth wheel head 136 may be pivotally attachedwith the trolley 132 through use of a pivot shaft 140. The fifth wheelhead 136 may be attached with the pivot shaft 140 in any appropriatemanner. By way of a non-limiting example, the fifth wheel head 136 maybe attached with the pivot shaft 140 through the use of fasteners,welding, or the like. The fifth wheel head 136 attached with the pivotshaft 140 may result in the fifth wheel head 136 being pivotable withrespect to the base frame 120. The pivoting of the fifth wheel head 136may allow the towed vehicle to pivot with respect to the towing vehicle108 during operation. Therefore, as the towing vehicle 108 turns, thefifth wheel head 136 may pivot independently of the towing vehicle 108.This may permit the towed vehicle to turn more efficiently andeffectively.

As shown in FIG. 6, the base frame 120 may include a pair of end rails146 and a pair of longitudinally extending rails 150. The rails 146, 150may be operatively secured together to form the base frame 120. By wayof a non-limiting example, fasteners 154 may be utilized to secure therails 146, 150 together. The present teachings, however, are not limitedto the use of fasteners 154. The rails 146, 150 may be attached such asthrough welding, being monolithically formed together, welded, orotherwise adhered together. The longitudinally extending rails 150 mayeach have a generally C-shaped cross sectional shape such that they eachinclude a channel 158. The channel 158 may be of a shape and size topermit rolling engagement of the trolley 132 with the base frame 120.

The base frame 120 may further include a cam plate 162 attached to thebase frame 120 in any appropriate manner. By way of a non-limitingexample, the cam plate 162 may be attached to an underside 166 of thelongitudinal rails 150 such as through the use of fasteners, welding orthe like. The cam plate 162 may include a cam path 170 formed therein.The cam path 170 may be formed as a monolithic unit with the cam plate162 or may be formed therein through a subsequent operation.

As shown in FIGS. 8, 9 and 10, the cam path 170 may be generallynon-linear. The cam path 170 being non-linear may permit the fifth wheelhead 136 to move rearward further within the same angular turn betweenthe towed and towing vehicle 108 during operation of the automaticrolling fifth wheel hitch 100. By way of a non-limiting example, thenon-linear cam path 170 may be formed from a plurality of linear pathsintegrated together to form the non-linear cam path 170. The non-linearcam path 170 may also be formed as an arcuate or semi-circular path.

As shown in FIG. 8, the cam path 170 may include two first paths orportions 175 that both extend in a generally angular direction from acenter section 177. First portions may be generally symmetrical aboutcenterline 181. The cam path 170 may also include second paths orportions 179 that may extend in a generally angular direction from endsof each first paths 175. These second portions 179 may extend at adifferent angle than the first portions 175 relative to centerline 181.By way of a non-limiting example, the first portions 175 may extend at agreater angle from a centerline 181 of the cam plate 162 than the secondportions 179. In some embodiments, the second portions 179 may also begenerally symmetrical one another, but the present teachings are notlimited to such. In operation, the second portions 179 may provide adifferent rate of movement of trolley 132 as the towing vehicle 108pivots relative to the towed vehicle as explained in more detail below.First and second portions 175, 179 may each be generally linear portions(i.e., each may extend in a generally continuous angular directionrelative to centerline 181).

As shown in FIG. 9, the cam path 170 may include two generally arcuateportions 183. The arcuate portions 183 may extend at any appropriaterelative angle from the centerline 185. By way of a non-limitingexample, the arcuate portions 183 may be in a generally concave shape asshown in FIG. 9. The arcuate portions 183 may be symmetrical relative toone another. As the cam path 170 extends at an arcuately downward angle,end portions 187 of the cam path are at a different relative angle tothe centerline 185 than top portions thereof. The curvature of arcuateportions 183 may provide a different rate of movement of trolley 132 asthe towing vehicle 108 pivots relative to the towed vehicle as explainedin more detail below.

As shown in FIG. 10, cam path 170 may include two generally arcuateportions 191. The arcuate portions 191 may extend at any appropriaterelative angle from the centerline 193. By way of a non-limitingexample, the arcuate portions 191 may be in a generally convex shape.The arcuate portions 191 may be symmetrical relative to one another. Asthe cam path 170 extends at an arcuately downward angle, end portions195 of the cam path are at a different relative angle to the centerline193 than top portions thereof. The curvature of arcuate portions 183 mayprovide a different rate of movement of trolley 132 as the towingvehicle 108 pivots relative to the towed vehicle as explained in moredetail below.

The trolley 132 may be shaped and sized to generally extend between thelongitudinally extending rails 150 and may include a portion of whichthat extends within the channel 158. More specifically, the trolley 132may include a body 174 that may be shaped and sized to extend betweenthe longitudinally extending rails 150 of the base frame 120. Thetrolley 132 may include a plurality of rollers or wheels 178 rotatablyattached to the body 174 in any appropriate manner. By way of anon-limiting example, four rollers 178 may be used—although anyappropriate number of rollers may be used without departing from thepresent teachings. As shown in FIG. 4, fasteners 182 may be used toattach the rollers 178 with the body 174. The present teachings,however, are not limited to use of fasteners 182. The rollers 178 may beattached with the body 174 in any appropriate manner.

The rollers 178 may be shaped and sized to operatively roll along thelongitudinally extending rails 150, or more specifically along thechannels 158 of the longitudinally extending rails 150. The rollers 178may be formed from a generally rigid material that has an effectivecoefficient of friction such that the rollers 178 may roll along thechannel 158 generally freely. Further, the rollers 178 may be of amaterial that generally prevents inappropriate wear during use of theautomatic rolling fifth wheel hitch 100 and is able to carry the load ofthe automatic rolling fifth wheel hitch 100 during operation. By way ofa non-limiting example, the rollers 178 may be formed from steel, orother metal, polymer, or other plastics, or a hard rubber, or acombination of such materials.

The trolley 132 may also include guide blocks 182. The guide blocks 182may be attached to the body 174 in any appropriate manner, including,without limitation through use of fasteners 190. By way of anon-limiting example, four such guide blocks 182 may be attached withthe body 174. The guide blocks 182 may be attached with the body 174such that they are generally adjacent the rollers 178, or morespecifically extend laterally away from the rollers 178 resulting in theguide blocks 182 being positioned on or near the corners of the trolley132. The guide blocks 182 may keep a generally tight, operative fitbetween the trolley 132, or more specifically, the rollers 178 and thechannel 158. The guide blocks 182 may control the axially upward anddownward movement as well as the fore and aft movement of the trolley132. The guide blocks 182 may also help control and guide the trolley132 during operation of the automatic rolling fifth wheel hitch 100. Theguide blocks 182 may be formed of any appropriate material, including,without limitation, polymer or other plastics, rubber, or a combinationof such materials.

Further, as shown in FIGS. 3, 4, 6 and 7, the channel 158 may begenerally enclosed on at least three sides with portions thereofextending downward and upward on a fourth side. This may form agenerally C-shaped cross-sectional shape. This shape of the channel 158may enclose the rollers 178 therein when operatively engaged. Thisenclosure may permit the automatic fifth wheel hitch 100, or morespecifically, the base frame 120 to be positioned generally lower in theload bed 104 of the towing vehicle 108. Prior art systems are typicallypositioned higher in the load bed. The base frame 120 being lower in theload bed 108 may result in a generally lower center of gravity for theautomatic fifth wheel hitch 100. Further, the base frame 120 may bewider than other prior art systems. The wider and lower base frame 120may allow for a tighter (i.e., more controlled movement) automatic fifthwheel hitch 100. The automatic fifth wheel hitch 100 may provideadditional control for an operator and is more efficient than otherprior art systems. Further, the automatic fifth wheel hitch 100 mayprovide a more direct load path, e.g., from top of the fifth wheel head136 to the rollers 178. The wider and lower base frame 120 may spreadthe load applied to the fifth wheel head 136 during operation down tothe trolley 132 and through to the legs 128 and ultimately to the towingvehicle 108. This may result in a more efficient and effective automaticfifth wheel hitch 100. The operation of which may be smoother and morestable than other prior art systems.

As shown in FIG. 4, once the trolley 132 has been assembled, it may beoperatively engaged with the base frame 120. Either one of the end rails146 may be removed from the base frame 120 or not otherwise attachedthereto. This may provide access between the trolley 132 and the channel158, or more specifically, the channel 158 and the rollers 178 of thetrolley 132. The trolley 132 may be rolled onto the base frame 120 suchthat the rollers 178 may freely roll within the channel 158. This mayresult in the trolley 132 being capable of rolling freely within thebase frame 120 generally between the end rails 146 during operation ofthe automatic rolling fifth wheel hitch 100 as described in more detailbelow.

The body 174 of the trolley 132 may include an aperture 194. Theaperture 194 may be shaped and sized such that the pivot shaft 140 maybe inserted within the body 174. The pivot shaft 140 may be insertedinto the aperture 194 so that it is pivotally attached with the body174. In such embodiments, a protective ring 198 may be generally alignedwith the aperture 194 and as the pivot shaft 140 is inserted into theaperture 194, the protective ring 198 may be positioned between thepivot shaft 140 and the body 174. The protective ring 198 may be made ofany appropriate material, including, without limitation a sacrificialmaterial. Further, by way of non-limiting examples, the material mayinclude elastomer, plastic, rubber, or any combination of such. Theprotective ring 198 being positioned between the body 174 and pivotshaft 140 may generally protect either or both of the pivot shaft 140and body 174 during operation of the automatic rolling fifth wheel hitch100. Additionally, the protective ring 198 may act as a lubricant orfriction reduction surface during operation of the automatic rollingfifth wheel hitch 100.

As shown in FIG. 7, a cam follower 202 may be operatively attached withthe trolley 132. In such embodiments, a cam follower protective ring 206may be generally positioned between the cam follower 202 and the body174 of the trolley 132. The protective ring 206 may be made of anyappropriate material, including, without limitation a sacrificialmaterial. Further, by way of non-limiting examples, the material mayinclude elastomer, plastic, rubber, or any combination of such. Theprotective ring 206 may generally protect either or both of the camfollower 202 and body 174 during operation of the automatic rollingfifth wheel hitch 100 (i.e., the rotating of cam follower 202 relativeto body 174). Additionally, the protective ring 206 may act as alubricant or friction reduction surface during operation of theautomatic rolling fifth wheel hitch 100. The cam follower 202 may beattached with the trolley 132 in any appropriate manner. By way of anon-limiting example, the cam follower 202 may attach with the trolley132 by a plurality of fasteners 210. Specifically, the fasteners 210 mayoperatively secure the cam follower 206 with the pivot shaft 140. Thefasteners 210 may be inserted into and connected with the trolley 132.

The cam follower 202 may include a body portion 214 and a cam portion218. The body portion 214 may be attached with the pivot shaft 140 whenit is inserted into and connected with the body 174 of the trolley 132.Therefore, as the pivot shaft 140 pivots, the cam follower 202 or morespecifically, the body portion 214 may pivot. The cam portion 218 mayinclude a contact member 222 that may be shaped and sized to operativelyfit within and engage the cam path 170. The contact member 222 mayfollow the cam path 170 during operation of the automatic fifth wheelhitch 100 and may be generally retained within the cam path 170. In thismanner, cam follower 202 is engaged with and follows cam path 170 duringoperation of automatic fifth wheel hitch 100.

In some embodiments, the automatic rolling fifth wheel hitch 100 mayinclude a cover 226 attached with the base frame 120. The cover 226 maygenerally encapsulates the base frame 120, trolley 132 and the cam plate162. More specifically, the cover 226 may generally encapsulate orcircumscribe the working components of the automatic rolling fifth wheelhitch 100. The cover 226 may provide an aesthetically pleasing finishfor the automatic rolling fifth wheel hitch 100. The cover 226 may alsogenerally protect the working components of the automatic rolling fifthwheel hitch 100 from the elements, which may extend the life thereof andmay generally protect operative engagement between the rollers 178 andthe channel 158.

In operation, the automatic fifth wheel hitch 100 may be attached to theload bed 104 of the towing vehicle 108 as described above. A king pin(not shown) of a towed vehicle (not shown) may be operatively securedwith the fifth wheel head 136 in any appropriate manner. Onceoperatively attached, the towing vehicle 108 may be operated. At thispoint any relative rotation between the towed vehicle and the fifthwheel head 136 may be inhibited by a detent section in the cam path asdescribed below. The towed vehicle may then be towed in the normalmanner by the towing vehicle 108. When the towing vehicle 108 and thetowed vehicle encounter a turn in the road, the towed vehicle may pivotrelative the towing vehicle 108. More specifically, under suchconditions the towed vehicle may pivot relative to the trolley 134 abouta vertical axis A that generally coincides with the fifth wheel head 136and as shown in FIG. 1.

When the towed vehicle pivots relative to the towing vehicle 108, thefifth wheel head 136, pivot shaft 140 and cam follower 202 may pivotrelative to the towing vehicle 108. The fifth wheel head 136, pivotshaft 140 and cam follower 202 may all be fixedly secured with oneanother such that they may pivot in unison. The trolley 132, however,will not pivot with respect to the load bed 104 of the towing vehicle108. The cam path 170 may include a detent section 230, such as thatshown in FIGS. 8, 9 and 10 generally in proximity to the fore and aftcenterline 181, 185 and 193, respectively of the cam plate 162. Thedetent 230 may form a normal operating position for the cam follower202. When the towing vehicle 108 is in a normal driving operation, e.g.,when driving generally straight and aligned with the towed vehicle, thecam follower 202 or more specifically the contact member 222 may beengaged in the detent 230, i.e., it may generally be positioned in thedetent 230. The detent 230 may be curved. Detent 230 may have endportions 231 that generally maintain cam follower 202 engaged in detent230 during normal driving operation and inhibit the contact member 222and cam follower 202 from moving along the cam path 170 outside ofdetent 230. However, when the fifth wheel head 136, pivot shaft 140 andcam follower 202 may be caused to pivot, such as by the turning oftowing vehicle 108 a sufficient amount relative to the towed vehicle,the cam follower 202 may move out from the detent 230 past end portions231 and travel further along cam path 170. The distance cam follower 202moves along cam path 170 may be related to the degree of relativepivoting between the towing vehicle 108 and the towed vehicle (i.e., thedegree of relative rotation between the fifth wheel head 136 and body174).

The cam follower 202 being released from the detent 230 may generallyallow the trolley 132 to roll towards a rear portion 234 of the towingvehicle 108 as the pivot angle between the towing vehicle and the towedvehicle changes. The momentum of the trolley 132 resulting from turningof the towing vehicle 108 may allow the rollers 178 to roll along thechannel 158. This momentum may continue to roll the trolley toward therear portion 234 of the towing vehicle 108 until at least one of theguide blocks 182 engages with the end rail 146 closest to the rearportion 234 of the towing vehicle 108. As the trolley 132 rolls towardthe rear portion 234 of the towing vehicle 108, the cam follower 202 maycontinue to move along the cam path 170 toward the rear portion 234 ofthe towing vehicle 108. This may result in the fifth wheel head 136traveling in conjunction with the trolley 132 rearward toward the rearportion 234 of the towing vehicle 108. This rearward movement of thefifth wheel head 136 may generally create additional space between a cab238 of the towing vehicle 108 and the towed vehicle. This additionalspace may thereby provide sufficient room for the towed vehicle to pivotwith respect to the towing vehicle 108 without interference.

For the cam plate 162 of FIG. 8, once the cam follower 202 releases fromthe detent 230, the cam follower 202 will follow along either of thegenerally symmetrical first portions 175. The shape and configuration ofcam path 170 may determine the rate and distance that trolley 132 movesin response to relative rotation between the towing vehicle 108 and thetowed vehicle. This relation may result in the towed vehicle movingbackward at greater distance and/or at a greater rate than the prior artsystems. The different configurations of the first and second portions175, 179 may result in the trolley 132 moving at a different rate and/ordistance in response to relative rotation between the towing vehicle 108and the towed vehicle. That is, when the cam follower 202 moves fromfirst portion 175 into second portion 179 (and vice versa), the relationbetween the rate of movement and/or the distance moved of trolley 132with respect to the change of the pivot angle between the towed vehicleand towing vehicle 108 changes. In the configuration shown in FIG. 8,the rate of movement and the distance moved by trolley 132 as a functionof the change in the pivot angle is less in second portion 179 than infirst portion 175. This configuration of the cam path 170 may allow thetowed vehicle to move away from the cab 238 at a greater rate, resultingin a greater distance between the cab 238 and the towed vehicle duringthe initial phase of relative rotation between the towing vehicle 108and the towed vehicle. Depending on the shape of detent section 230 andend portions 231, the towed vehicle may experience an initial forwardmovement relative to the towing vehicle 108 as cam follower 202 movesout of the detent section 230. The movement of the trolley 132 as afunction of the change in the pivot angle is represented in the graph ofFIG. 11. As shown, the trolley may undergo a first motion A as camfollower 202 moves out of detent section 230, a second motion B as camfollower 202 moves along first portion 175, and a third motion C as camfollower 202 moves along second portion 179.

For the cam plate 162 of FIG. 9, once the cam follower 202 releases fromthe detent 230, the cam follower 202 will follow along either of thegenerally arcuate portions 183. The shape and configuration of cam path170 may determine the rate and distance that trolley 132 moves inresponse to relative rotation between the towing vehicle 108 and thetowed vehicle. This relation may result in the towed vehicle movingbackward at greater distance and/or at a greater rate than the prior artsystems. The arcuate configuration of path 183 may result in acontinuously varying rate of movement and distance traveled by trolley132 as a function of the change in the pivot angle. The movement of thetrolley 132 as a function of the change in the pivot angle as camfollower 202 moves along arcuate path 183 may be represented by thegraph of FIG. 12. As shown, trolley 132 may undergo a first motion A ascam follower 202 moves out of detent section 230 and a second motion Bas cam follower 202 moves along arcuate portion 183. As can be seen insecond motion B, trolley 132 moves a shorter distance and at a slowerrate as the pivot angle increases. That is, as the cam follower 202moves along the arcuate path 183 toward the end portion 187, therelation between the distance traveled and the rate of travel inresponse to a change of the pivot angle changes.

For the cam plate 162 of FIG. 10, once the cam follower 202 releasesfrom the detent 230, the cam follower 202 will follow along either ofthe generally arcuate portions 191. The shape and configuration of campath 170 may determine the rate and distance that trolley 132 moves inresponse to relative rotation between the towing vehicle 108 and thetowed vehicle. This relation may result in the towed vehicle movingbackward at greater distance and/or at a greater rate than the prior artsystems. The arcuate configuration of path 191 may result in acontinuously varying rate of movement and distance traveled by trolley132 as a function of the change in the pivot angle. The movement of thetrolley 132 as a function of the change in the pivot angle as camfollower 202 moves along arcuate path 191 may be represented by thegraph of FIG. 13. As shown, trolley 132 may undergo a first motion A ascam follower 202 moves out of detent section 230 and a second motion Bas cam follower 202 moves along arcuate portion 191. As can be seen insecond motion B, trolley 132 moves a greater distance and at a greaterrate as the pivot angle increases. That is, as the cam follower 202moves along the arcuate path 191 toward the end portion 1195, therelation between the distance traveled and the rate of travel inresponse to a change of the pivot angle changes.

As the towing vehicle 108 straightens out and returns from a turningposition to a straight ahead position (aligned with the towed vehicle)the change in the pivot angle will move cam follower 202 forward alongthe cam path 170 toward detent 230. The fifth wheel head 136, pivotshaft 140 and cam follower 202 will all pivot back towards astraightened position and trolley 132 will move forward. Once the towingvehicle 108 straightens out a sufficient distance, the cam follower 202may engage the detent 230 of the cam plate 162.

Additional embodiments of an automatic rolling fifth wheel hitchaccording the present teachings are described below. In thedescriptions, all of the details and components may not be fullydescribed or shown. Rather, the features or components are describedand, in some instances, differences with the above-described embodimentsmay be pointed out. Moreover, it should be appreciated that theseadditional embodiments may include elements or components utilized inthe above-described embodiments although not shown or described. Thus,the descriptions of these additional embodiments are merely exemplaryand not all-inclusive nor exclusive. Moreover, it should be appreciatedthat the features, components, elements and functionalities of thevarious embodiments may be combined or altered to achieve a desiredautomatic rolling fifth wheel hitch without departing from the spiritand scope of the present teachings.

An automatic rolling fifth wheel hitch 300 is shown in FIGS. 14-16. Theautomatic rolling fifth wheel hitch 300 may attach to a load bed 104 ofa towing vehicle 108 in any appropriate manner. The automatic rollingfifth wheel hitch 300 may include a base frame 320 selectively securedto the rail members 112. The base frame 320 may include at least onebracket 324, including, without limitation two pairs of brackets 324attached thereto. The brackets 324 may attach with the rail members 112through the use of fasteners (not shown).

The automatic rolling fifth wheel hitch 300 may include a trolley 332operatively engaged with the base frame 320 as described in more detailbelow. The automatic rolling fifth wheel hitch 300 may further include afifth wheel head 336 pivotally attached with the trolley 332. The fifthwheel head 336 may be of any appropriate configuration such that a kingpin of a towed vehicle may operatively engage with the fifth wheel head336 resulting in the towing vehicle 108 being capable of towing thetowed vehicle.

The fifth wheel head 336 may be pivotally attached with the trolley 332through use of a pivot shaft 340. The fifth wheel head 336 may beattached with the pivot shaft 340 in any appropriate manner. By way of anon-limiting example, the fifth wheel head 336 may be attached with thepivot shaft 340 through the use of fasteners, welding, or the like. Thefifth wheel head 336 attached with the pivot shaft 340 may result in thefifth wheel head 336 being pivotable with respect to the base frame 320.The pivoting of the fifth wheel head 336 may allow the towed vehicle topivot with respect to the towing vehicle 108 during operation.Therefore, as the towing vehicle 108 turns, the fifth wheel head 336 maypivot independently of the towing vehicle 108. This may permit the towedvehicle to turn more efficiently and effectively.

The trolley 332 may be shaped and sized to generally extend with thebase frame 320 and may include a portion of which that extends within achannel 358 of the base frame 320. More specifically, the trolley 332may include a body 374 that may be shaped and sized to extend betweenthe base frame 320. The trolley 332 may include a plurality of rollersor wheels 378 rotatably attached to the body 374 in any appropriatemanner. By way of a non-limiting example, four rollers 378 may beused—although any appropriate number of rollers may be used withoutdeparting from the present teachings.

The rollers 378 may be shaped and sized to operatively roll along thechannels 358 of the base frame 320. The rollers 378 may be formed from agenerally rigid material that has an effective coefficient of frictionsuch that the rollers 378 may roll along the channel 358 generallyfreely. Further, the rollers 378 may be of a material that generallyprevents inappropriate wear during use of the automatic rolling fifthwheel hitch 300 and is able to carry the load of the automatic rollingfifth wheel hitch 300 during operation.

The automatic rolling firth wheel hitch 300 may include a plate member381 attached with the base frame 320 in any appropriate manner,including, without limitation through welding, fastening or the like.Further, a linkage 385 may be operatively secured with the fifth wheelhead 336 through the pivot shaft 340 and the plate member 381. As shownin FIGS. 14-15, the linkage 385 may include a first arm 387 fixedlyattached with the pivot shaft 340 and fifth wheel head 336. By way of anon-limiting example, the first arm 387 may be fixedly attached with thepivot shaft 340 such as through the use of a plurality of fasteners 389.The first arm 387, however, may be fixedly attached with the pivot shaft340 and fifth wheel head 336 in any appropriate manner and is notlimited to the fasteners 389 shown. First arm 387 may act as a bellcrank.

The linkage 385 may further include a second arm 391. The second arm 391may be pivotally attached between the first arm 387 and the plate member381. By way of a non-limiting example, the second arm 391 may bepivotally attached with the first arm 387 at pivot 393, such as throughuse of a fastener 395. Any appropriate fastener 395 may be used withoutdeparting from the present teachings. The second arm 391 may also bepivotally attached with the plate member 381 at a second pivot 397, suchas through use of a fastener 399. Any appropriate fastener 397 may beused without departing from the present teachings. In some embodiments,the fastener 395 may be substantially similar to the fastener 399 orthey may be different.

In operation, when the towing and towed vehicles are generally aligned,the first and second arms 389, 391 of the linkage 385 may remaingenerally aligned. As the towing vehicle pivots with respect to thetowed vehicle, the fifth wheel head 336 may pivot, which may pivot thepivot shaft 340 and the first arm 387. As the first arm 387 pivots, thismay cause the first arm 387 and second arm to pivot at pivot point 393.The pivoting of the linkage 385, or more specifically, the first arm 387relative to the second arm 391, may cause the trolley 332 to bedisplaced rearward toward the rear of the towing vehicle, i.e., themomentum causes the rearward movement of the trolley 332. Further, thesecond arm 391 may pivot with respect to the plate member 381 at pivot397. This motion of the trolley 332 may move the attachment point of thetowed vehicle with the towing vehicle rearward. This may create agreater clearance between the towed vehicle and towing vehicle.Specifically, it may create more space between the cab of the towingvehicle and the towed vehicle.

Once the towing and towed vehicles have completed the turn and begin tostraighten, the momentum of such may force the trolley 332 forward. Thismay cause the linkage 385 to straighten, i.e., the first arm 387 andsecond arm pivot 391 until they are generally aligned. This may move thetowed vehicle in closer proximity to the towing vehicle's cab returningthe automatic rolling fifth wheel hitch 300 to its normal operatingposition.

It should be appreciated that the various cam paths shown and describedare exemplary cam paths and that variations can be made. By way ofnon-limiting example, the cam paths can take other shapes andconfigurations and may include or exclude the detent.

Although the embodiments of the present invention have been illustratedin the accompanying drawings and described in the foregoing detaileddescription, it is to be understood that the present invention is not tobe limited to just the embodiments disclosed, but that the inventiondescribed herein is capable of numerous rearrangements, modificationsand substitutions without departing from the scope of the claimshereafter. The claims as follows are intended to include allmodifications and alterations insofar as they come within the scope ofthe claims or the equivalent thereof.

Having thus described the invention, the following is claimed:
 1. Afifth wheel hitch comprising: a base frame; a trolley operativelyengaged with the base frame, the trolley moveable along the base framebetween first and second positions; a cam member attached with the baseframe, the cam member having a cam path; a cam follower coupled with thetrolley, the cam follower operatively engaged with the cam path; and afifth wheel head pivotally coupled with the trolley, wherein the trolleyis moved between the first and second positions in response to pivotingof the fifth wheel head.
 2. The fifth wheel hitch of claim 1, whereinthe base frame includes a channel whereby the trolley is operativelyengaged with the base frame.
 3. The fifth wheel hitch of claim 2,wherein the trolley includes a plurality of rollers, the rollers engagedwith the channel and the trolley rolls along the base frame between thefirst and second positions.
 4. The fifth wheel hitch of claim 2, furthercomprising a plurality of guide plates, wherein the guide plates areengaged with the channel.
 5. The fifth wheel hitch of claim 1, whereinthe cam path includes a detent, the cam follower engaging the detentwhen in the first position and whereby pivoting of the fifth wheel headmoves the cam follower from the detent and permits the trolley to movealong the base frame to the second position.
 6. The fifth wheel hitch ofclaim 1, wherein the cam path is non-linear, whereby the cam followeroperatively engages the non-linear cam path during rolling movement ofthe trolley.
 7. The fifth wheel hitch of claim 1, wherein the cam pathincludes a first portion causing the trolley to move between the firstand second positions at a first rate as the fifth wheel head pivots. 8.The fifth wheel hitch of claim 7, wherein the cam path includes a secondportion causing the trolley to move between the first and secondpositions at a second rate as the fifth wheel head pivots whereby thesecond rate is different from the first rate.
 9. The fifth wheel hitchof claim 8, wherein the second portion is at a different pivot angle ofthe head relative to a centerline of the cam member than the firstportion.
 10. The fifth wheel hitch of claim 8, wherein the second rateis less than the first rate.
 11. The fifth wheel hitch of claim 10,wherein the second portion is closer to the second position than thefirst portion.
 12. The fifth wheel hitch of claim 1, further comprisinga plurality of guide blocks positioned on the trolley.
 13. The fifthwheel hitch of claim 12, wherein the guide blocks engage the base framegenerally preventing vertical movement of the trolley with respect tothe base frame.
 14. The fifth wheel hitch of claim 12, wherein the guideblocks limit fore and aft movement of the trolley with respect to atowing vehicle.
 15. A fifth wheel hitch comprising: a base frameincluding a channel; a trolley having a plurality of rollers, therollers operatively engaged with the channel, wherein the trolley ismoveable between first and second positions with respect to the baseframe; a cam path, the cam path having a first portion; and a camfollower coupled with the trolley, the cam follower operatively engagingthe first portion of the cam path, wherein pivoting of the cam followerreleases the cam follower from the first portion permitting movement ofthe trolley fore and aft between the first and second positions.
 16. Thefifth wheel hitch of claim 15, further comprising a cam plate, the camplate attached with the base frame, whereby the cam path is formed inthe cam plate.
 17. The fifth wheel hitch of claim 15, wherein the firstportion is an arcuate detent section in the cam path.
 18. The fifthwheel hitch of claim 17, wherein the cam follower moving from the detentmoves the trolley forward to the first position.
 19. The fifth wheelhitch of claim 17, further comprising a fifth wheel head pivotallyengaged with the trolley, wherein pivoting of the fifth wheel head movesthe cam follower out of the first portion of the cam path permitting thetrolley to move to the second position.
 20. The fifth wheel hitch ofclaim 19, wherein the trolley is moveable fore and aft relative to thetowing vehicle.